newsletter

How does a cut know to stop bleeding?

Ouch! When you’ve accidentally cut or scraped yourself, there’s something in your body that responds with help right away, without you even knowing it! That special helper is platelets.

Have you ever heard of platelets before? Along with certain types of cells and a liquid called “plasma,” platelets make up your blood. Platelets are extremely tiny (way too small to see without a microscope!) but they have a very important job: helping your blood to form clots (like scabs) when you’re bleeding.

When you get a cut that bleeds, platelets rush to the scene of the accident! Platelets are sticky, so they can attach to each other and start to block the bleeding. Other things in your body (like calcium and certain vitamins and protein) join together with the platelets to form a covering over the wound. This covering dries and hardens into a scab, which keeps the injury closed while your skin heals underneath! – Thanks, platelets!

Further information

Remember that even though platelets are there to help you, you always need to take care with cuts and scrapes. If you or someone else is bleeding, get help from a grown-up right away and never touch somebody else’s wound. Some cuts are too big for platelets to handle on their own, and might need help from a doctor or nurse.